Can you crack mystery of 230-year-old rock inscription?

The challenge has been set for anyone able to uncover what a mysterious 230-year-old rock inscription means.

Villagers in France are even offering prize money of £1,750 (€2,000) to anyone able to crack the code.

The unknown message – which includes 20 lines of text in both French and Scandinavian characters – was discovered on rocks hidden inside a cave around five years ago.

It has so far left historians and decoders baffled but hasn’t stopped several wild conspiracy theories emerging among locals in the town of Plougastel-Daoulas, in north west France’s administrative region of Brittany.

Some have suggested that the text may relate to the establishments of fortifications near the cove in which the rock is found.

The 1-metre tall rock is only accessible when the tide goes out and has been dated to around 1789.

Plougastel mayor, Dominique Cap, who set the competition to run until November, said he has already received thousands of submissions.

French local councillor Michel Paugam poses with the indecipherable words (Picture: AFP/Getty)

He added: ‘We’ve asked historians and archaeologists from around here, but no-one has been able to work out the story behind the rock.

‘So we thought [that] maybe out there in the world there are people who’ve got the kind of expert knowledge that we need.

‘Rather than stay in ignorance, we said: let’s launch a competition.’

Some of the characters carved into the rock are normal French letters depicted in reverse or upside down, while others appear to be ‘Ø’, which is a vowel in the Scandinavian languages of Danish, Norwegian, Faroese, and Southern Sami.

Municipal Councillor Michel Paugam, who is in charge of local heritage, told AFP:’There are a lot of words but we can’t read them, we can’t make them out.’

What carvings can be made out?

Plougastel-Daoulas has launched a national call to anyone able to solve the mystery of these inscriptions (Picture: AFP/Getty)

The rock features the image of a ship, complete with sails and a rudder, and what appears to be a sacred heart — a heart covered by a cross.

Two apparent dates are also visible, 1786 and 1787, which would place the inscription to a few years before the onset of the French Revolution.

It is believed the inscriptions were probably made during the 18th century (Picture: AFP/Getty)

Veronique Martin, who is leading the hunt for someone to crack the code, said: ‘These dates correspond, more or less, to the years that various artillery batteries protected Brest and notably Corbeau Fort which is right next to [the cove].’

Brest is a port city that lies on the opposite side of the bay to Plougastel-Daoulas.

Local experts think that the words might be written either in old Breton, a now-extinct language that was spoken in Northern France between the 9th and the 11th century AD.

Others believe it may be written in Basque, a language spoken in Basque Country, on the French-Spanish border.

It could be that the person who wrote the words may have been semi-literate, experts have speculated.